Drill



May 17, 1932.

J.- v'. EMMONS 1,859202 DRYLL Filed Sept. 8, 1928 INVENTOR.

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tool for ated but which Patented M0117, 1932 PATENT OFFICE JOSEPH V. EMHONS, OF HEIGHTS, OHIO,

' DRILL CC MPANY, OF CLEVELAND, OHIO,

ASSIGNOIB 1'0 TEE ELAND' TWIED A CORPORATION OF OHIO mum:

Application filed. September 8, 1928. Serial R0. $04,748.

The present invention, relating, as indicated, to drills,'has more especial reference to drills of the impact or percussion type, and its principal object is to provide an im roved the rapid and efficient drilling of holes in such materials as bricks, stone, concrete, etc.

More specifically, my invention contemplates the provision of a drill having a handle portion and an integral operating portion, the former. portion being adapted for holding in the hand during the drilling operation, and the latter portion being provided with helical flutes for carrying the cuttings towards the mouth of the hole and with a special cutting point which not only has a rapid action in the materials above enumercan also be originally formed and thereafter maintained in the desired condition of sharpness by simple grinding operations which neither consume an excessive amount of time nor require the use of any very elaborate or complicated equipment. Further features of the drill which constitute this invention are the lands or flukes of uniform diametenand an abnormally thick web between the conveying grooves, these providing adequate metal for supporting the cutting edges'and insuring suflicient stiffness or rigidity for resisting the impact of the driving tool as well as obviating the necessity for frequent resharpening and permitting of an" unusually rapid rate of hole formation.

To the accomplishment of the foregoing and relatedends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims; the annexed drawings and the following description setting forth in detail certain struc ture embodying the invention, means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings:-

Fig. 1 is a side elevational view of a drill embodying the present improvements; Fig. 2 is a plan view ofthe cutting point; Fig. 3 is a fragmentary side elevational view taken at right angles to the position represented in such disclosed Fig. 1; and Fig. 4 is a plan view of the shank or handle.

That embodiment of my invention illustrated in the drawings consists of a shank or handle portion 10 and an operating portion 11. The shank 10 is preferably formed integral with the operating portion 11 and is desirably of such size,'shape and finish as to be conveniently held in the handduring the drilling operations. By way of exemplification, such handle is represented as being octagonal in cross section but other polygonal shapes or a round section, especially if roughened or knurled topermit of a firm grip, are also suitable. In order to provide a more satisfactory striking surface for receiving the blows from a hammer or other adapted impact means and preventing undue flaring or battering, the end 12 may be flattened and its edge 13 chamfered or beveled as shown in Figs. 1 and 4.

he operating portion 11 may be of any desired or necessary length and in diameter is preferably, although not essentially, of somewhat smaller section than the handle 10.

It is provided with a plurality, say two, of

helical grooves or flutes 14, and between such grooves are the lands or flukes 15, these latter being shown as of uniform diameter and formed without clearance to the .rear of or behind their leading edges 16. However, in some cases, it may be found desirable to provide a certain degree of longitudinal clearance b making the tool of smaller diameter at the a'ck end than at the point. Furthermore, clearance to the rear of or behind the cutting edges or margins 16 of the lands may be provided so long as such clearance is not carried to the point of the tool so as to reduce the diameter at the cutting edges hereinafter referred to. The cutting point is of such a form as to be capable of eflicient and rapid four de-.

preferably smaller facets 20 and 21, the latter two resulting in or causing inclination of the 1 cutting edges 22 and 23 away from the point 17. As clearly shown in Figs. 1 and 3 the uniform diameter of the lands is effective I to lengthen the cutting edges 24, this resulting in a more satisfactory and expeditious action in rounding out the hole as preliminaril formed by the edges 22 and 23.

n use, my improved drill is preferablyheld in the hand and rotated between the successive blows in order to bring the cutting point tend its use in the manual methodabove explained. When through continued use in the drilling of holes in such materials as bricks, stone, and concrete, the cutting point and its cutting edges become dull, such parts may be restored to their original condition by regrinding the point facets, these being especially positioned to not only provide for rapid and eflicient drilling action' but to also make possible their initial application and subsequent sharpening with a minimum expendi- .ture.0f time and with great facility. Be-

cause of the fact that the web thickness between the conveying flutes is uncommonly great, and because of the further fact'that the lands are of one uniform diameter throughout the length of the operating portion of the tool, such portion is of ample rigidity and the cutting edges and fluke leads are backed up with sufiicient metal so that both the liability to breakage or deformation and the necessity for too frequently dressing the cutting point and land edges are obviated and the tool as a whole is better adapted for prolonged use under severe conditions of service.

Other modes of applying the principle of, my invention may be em loyed'instead. of

ing made as regards the structure herein disclosed, provided I the one explained, change the means stated by any of the following claims or the equivalent-of such stated means be employed. i

I therefore particularly point out and distinctly claim as my invention 1. A percussiondrill, comprising a blowreceiving shank portion, and an operatin portion having a cutting end in the form o a four-sided pyramid with alternate lar and'small facets, and two helical flutes term-1- mating in certain of the facets.

2. percussion drill, comprising a blowreceiving shank portion, an an operating portion having a cutting end in the form of a four-sided pyramid with alternate large and small facets, and helical flutes terminating in each large facet.

3. A percussion drill,'comprising a blowreceiving shank portion, and an operating portion having a cutting end in the form of a foursided pyramid with alternate large and small facets, helical flutes terminating in each large facet, and an arcuate reaming edge at the outer border of each facet.

4. A percussion drill, comprising a blowreceiving shank portion, and an operating portion having a cutting end in the form of a four-sided pyramid, and two.helical flutes terminating in certain of said sides.

5. A percussion drill, comprising a blowreceiving shank portion, and an operating portion having a cutting end in the form of a four-sided pyramid, and two helical flutes terminating in certain of said sides, said sides having arcuate reaming edges at their outer borders. 1

Signed by me, this 6th day of September,

JOSEPH v. EMMONS. 

